[WinterRampage]

I'll try charging with the provided cable as soon as i'll get home, which is tomorrow afternoon. I don't know if removing the case (for making sure that the battery is fit?) would void the warranty.

As for the hard reset, that's not possible since it doesn't even start. From what i know, it must reach the "Opening book" loading screen in order to do it.

Now the bad news. I can't find neither the receipt nor the warranty card (the one issued from the store I bought it from, not the card inside the box from Sony, which is unpersonalized). I asked them if the serial is written on the small sticker with 7 digits on the lower left back corner, but they said it's on the warranty card. I believe the Serial Number should be written somewhere on or inside the reader. Anyone knows where? Also, if it's inside, would removing the case void the warranty?

Edit: It's possible that I'm misinterpreting the email I received. It literally says (translation): "Also, the product's SN is on the warranty certificate, which proves from where (as in from which shop) you've bought the product". I'm not sure whether this means that the sticker doesn't list the SN or if they need the warranty certificate because they don't have the SN in a database.

Edit2: Just in case I don't manage to make them fix it: is it possible to have it repaired at a Sony Center for a fee?